<i>In vitro</i> cystein protease inhibitory activity of selected Indian antimalarial plants

Abstract

In this study few plants having antimalarial activity (leaves of <em>Nyctanthes arbor-tristis </em>L<em>., Caesalpinia crista </em>L.<em>, </em><em>Ailanthus&nbsp;excelsa&nbsp;</em>Roxb<em>.</em><em>, Bauhinia variegate </em>L<em>.</em>, seed of <em>Balanites aegyptiaca </em>Delile, entire plant of <em>Enicostema littorale </em>Blume, fruits of <em>Momordica charantia </em>L<em>.</em>) were screened for cystein protease inhibitory activity. Cysteine protease inhibitory activity was done by papain inhibition assay. Water and methanol extracts of all selected plants were screened for <em>in vitro</em> enzyme inhibition assay. Percentage inhibition of papain was measured and IC₅₀for all the extracts were calculated. Comparative study of above selected medicinal plants methanolic and water extract showed the maximum inhibition in leaves of <em>N. arbor-tristis, </em>87.8051 %, IC₅₀ &ndash; 13.03 &micro;g/ml and 85.6189 %, IC₅₀ - 16.54 &micro;g/ml, respectively. The present study has provided scientific validity to leaves of <em>N. arbor-tristis </em>against cysteine protease inhibition activity and it is concluded that protease inhibitor of <em>N. arbor-tristis </em>leaves are an indicator of wide range of pharmacological activities such as anticancer, antimalarial, osteoarthritis, osteoporosis, etc.<em>, </em>isolation of cysteine protease inhibitors may provide a lead compound for development of novel therapeutic agents in the above areas.